The invention relates to compounds useful in the synthesis of analogs of halichondrin B.
Eribulin mesylate, a nontaxane microtubule dynamics inhibitor, is a structurally simplified, synthetic analog of the marine natural product halichondrin B. Methods for the synthesis of eribulin and other halichondrin B analogs are described in International Publication No. WO 2005/118565 and U.S. Pat. No. 6,214,865. New intermediates for the synthesis of halichondrin B analogs, in particular eribulin, are desirable.